Lyonnaise potatoes

Lyonnaise potatoes
Prepare
less than 30 mins
Cook
1 to 2 hours
Serve
Serves 6 as a side, 4 as a main

Traditionally this French dish is sautéed on the hob, but if you’re serving it as a Sunday roast accompaniment all that last-minute fuss can be a distraction. This is finished in the oven instead.

Lyonnaise potatoes also make a great vegetarian supper served with some sharply dressed salad leaves.

By Sarah Cook

Shopping list

Ingredients

  • 3 large onions, sliced
  • 2 tbsp olive oil
  • 50g/1¾oz butter
  • 1.2kg/2lb 12oz medium potatoes, like Desiree, Maris Piper or Elfe, peeled
  • 2 tbsp finely chopped flatleaf parsley, plus extra to serve if you like
  • 2 tbsp fresh thyme leaves, plus extra to serve if you like
  • 2 garlic cloves, thinly sliced
  • salt and freshly ground black pepper
Recipe tips
How-to videos

Method

  1. Put the sliced onions, olive oil and half the butter in your largest frying pan. Cook over a low-medium heat until the onions are super-soft but not golden-brown yet – this might take up to 30–35 minutes.

  2. Meanwhile bring a large pan of salted water to the boil. Slice the potatoes into 1cm/½ in thick slices. Once the water is boiling, add the potatoes and when the water has returned to the boil, set your timer for 3 minutes. Drain immediately and leave in the colander to steam dry.

  3. Preheat the oven to 200C/180C/Gas 6.

  4. When the onions are done, remove from the heat. Stir through the parsley, thyme, garlic and some generous seasoning. Gently toss the onion mixture and par-boiled potatoes together – you can do this in the frying pan if they fit, or a large mixing bowl.

  5. Tip everything into a large baking dish – you don’t want the mixture to sit any deeper than 5cm/2in. Arrange and press the top down a little to roughly flatten. Dot the remaining butter all over the top.

  6. Bake for 35–40 minutes, or until the top is golden-brown and crisp, and the potatoes cooked through. A little extra garnish of chopped parsley and fresh thyme is nice, but not strictly necessary.

Recipe tips

You can get ahead by preparing the Lyonnaise potatoes up to the end of step 5. They'll keep in fridge for several hours ahead.

Make this recipe vegan by replacing the butter with more oil.

Other potato sides that feel fancy but can easily be prepared ahead include dauphinoise potatoes and boulangère potatoes.